7 days ago
Fossil Coast Drinks Co welcomes Dr Liam Herringshaw as a guest blogger sharing his knowledge, experience and expertise in discovering the fossils of Whitby. Located on the North Yorkshire coast this sea side harbour town is famous for the summer visit of Irish writer Bram Stoker in 1890. Influenced by the spectacular backdrop of the windswept Abbey Headland and the historic ruins of Whitby Abbey he would later go onto pen the gothic horror novel of Dracula first published in 1897.
It may not be a UNESCO World Heritage site, but the Yorkshire Coast is one of the best places in the world to find Jurassic fossils. Whitby is right at the heart of it.
In 2023, the Yorkshire Fossil Festival came to town to celebrate the 200th anniversary of the Whitby Literary & Philosophical Society, whose marvellous Whitby Museum gazes out across the harbour from its hillside residence in Pannett Park. Inside, treasures of every imaginable variety fill glass-and-timber cabinets from floor to ceiling.
To an aspiring palaeontologist, the geology gallery is especially enticing, showing off some of the best discoveries made over the last two centuries.
But how might you find your own?
The simple answer is to pick through pebbles on the town’s beaches, but you need to do this safely and responsibly. Check the tide times and only go out on a falling tide. Check the weather forecast and make sure you’re prepared for cold, wet or windy conditions. And stay away from the cliffs! Each year, there are thousands of rockfalls on the Yorkshire Coast, and no fossil is worth serious injury.
Ammonites are perhaps the quintessential Whitby fossils. Most days you can find people searching the shingle for rounded, grey, fist-sized cobbles. Slightly flattened ones sometimes show a wrinkled or lined pattern around their middle, making them look a bit like a monochrome burger. With careful work by a skilled preparator they can reveal beautifully preserved ammonites.
These curly ancient mollusc shells get their name from their resemblance to the horns of the Egyptian god Ammon. Whitby’s early Jurassic specimens, however, have a different origin story.
St Hild was in charge of the town’s abbey in the 7th Century, and it is said she had petrifying powers. Using these against the devilish local serpents, St Hild turned them to stone, and cast them down onto the beaches below the abbey.
Enterprising local craftspeople sometimes carved heads onto these ‘snakestones’ and a distinctive local ammonite is named Hildoceras in her honour. Another form is commonly found in pieces that look like a wrinkled finger: hence its name, Dactylioceras, or the ‘finger-horn’. Saltwick Bay to the east of the town and Sandsend to the west are two of the best places to go ammonite-spotting.
If you take a stroll along Whitby’s sandy West Beach, you’ll make footprints, at least until the tide comes in. Had you been there 170 million years earlier, when the sandstone cliffs were part of a Middle Jurassic coastal plain, you’d have been making your mark in the company of giants. Fossilised footprints found in these rocks reveal that many different dinosaurs roamed the ancient shorelines, including theropods, stegosaurs, and sauropods.
Being (mostly) large creatures, dinosaurs made a big impression. This increased their footprints’ chance of fossilisation. Also, Jurassic Yorkshire was in Mediterranean latitudes, so the hot summer sun sometimes baked trampled sediments before a current could wash the footprints away. Nonetheless, tiny tracks also get preserved, whilst dino bones almost never do, so something quite surprising was still going on.
Unlike body fossils, which simply record where something dead was buried, footprints are the trace fossils of living creatures. Place your foot on a dinosaur footprint and you are standing where they stood, walking where they walked, living where they lived. And where they still live: birds are now known to be theropod dinosaurs, so there are dinosaurs all around us. Console yourself with this when a herring gull steals your chips on Whitby pier.
Stroll the cobbled streets of Whitby’s old town and you might notice a fair few jewellers. This is because Whitby has its very own Jurassic gemstone: jet. Treasured by people for thousands of years, its recent popularity connects Queen Victoria’s mourning with 21st Century goths.
Jet’s ancient origins hark back to Jurassic logs drifting out into a warm, shallow, muddy sea, and becoming buried as a unique form of sea coal.
Rather than being brittle like most coal (which formed in peaty swamps), jet has oils locked within its structure that give it a lustrous, soapy texture. Perfect for skilful jewellers to work with.
In many of the shops (and Whitby marketing materials) you’ll read that Whitby jet is fossilised monkey puzzle tree.
Whitby-based gemmologist and geoarchaeologist Sarah Caldwell Steele, form Ebor Jetworks, has shown this is not true. There were plenty of conifers around in Early Jurassic Yorkshire, and some of them are relatives of living Araucaria, but Whitby jet is not the product of a single type of tree, or a modern monkey puzzle tree.
Many types of Jurassic tree became jet, and all of them are trees that are now extinct.
Why Whitby has such amazing fossils is something we also need to consider. Jurassic sedimentary rocks are found in many places, but they don’t all attract palaeontologists. The reason Whitby does is thanks to ancient climate change.
Around 183 million years ago, during the Toarcian stage of the early Jurassic, volcanic activity in what is now South Africa drove a period of rapid global warming. This caused glaciers to melt and sea-levels to rise. Continental shelves became flooded by the seas whilst intense storms washed huge volumes of nutrients off the land. In shallow, sunlit waters, plankton bloomed. The oxygen in the seawater was quickly used up near the surface: deeper down the water and sediment became stagnant and stinky. Animals could no longer live on the seafloor.
International research indicates that the Whitby area was particularly badly hit. The anoxia (lack of oxygen) on the seafloor lasted for hundreds of thousands of years. Many species became extinct. But while it was terminal for Toarcian critters, it was great for future fossil-hunters. The anoxic event ensured bodies (animal and plant) that sank to the seabed didn’t get scavenged or disturbed. Ammonites, tree trunks, crustaceans and reptiles were preserved for posterity.
If Whitby’s Jurassic fossils weren’t enough, there’s more. Thanks to the glaciers of the last Ice Age, around 20,000 years ago, much of North Yorkshire’s bedrock is draped in till. Commonly known as boulder clay, this sticky, cobbly sediment contains a huge mix of rocks transported by ice from further north, including Scotland and Scandinavia.
The till is also easily eroded. As a result, its cargo gets washed out onto the beaches. Many of these glacial erratic's are igneous or metamorphic, but plenty are sedimentary too. Beautiful Carboniferous corals and fossil plants are frequently picked up, hundreds of miles and millions of years from home.
A Whitby trip is time-travelling at its best!
Earlier this year Fossil Coast Drinks Co headed to the North East of England and Redcar on the North Yorkshire coast for the Yorkshire Fossil Festival.
This wonderful festival was celebrating its 10th birthday and was organised by palaeontologist Dr Liam Herringshaw (@fossiliam) and geologist and education specialist Steve Cousins known as the The Rock Showman.